Saturday, February 13, 2016

(Replicator Technology) Matter Will Be Created From Light Within A Year, Claim Scientists

In a neat demonstration of E=mc 2, physicists believe they can create electrons and positrons from colliding photons

Researchers
have worked out how to make matter from pure light and are drawing up
plans to demonstrate the feat within the next 12 months.

The
theory underpinning the idea was first described 80 years ago by two
physicists who later worked on the first atomic bomb. At the time they
considered the conversion of light into matter impossible in a
laboratory.

But in a report published on Sunday, physicists at
Imperial College London claim to have cracked the problem using
high-powered lasers and other equipment now available to scientists.

“We
have shown in principle how you can make matter from light,” said
Steven Rose at Imperial. “If you do this experiment, you will be taking
light and turning it into matter.”

The scientists are not on the
verge of a machine that can create everyday objects from a sudden blast
of laser energy. The kind of matter they aim to make comes in the form
of subatomic particles invisible to the naked eye.

The original
idea was written down by two US physicists, Gregory Breit and John
Wheeler, in 1934. They worked out that – very rarely – two particles of
light, or photons, could combine to produce an electron and its
antimatter equivalent, a positron. Electrons are particles of matter
that form the outer shells of atoms in the everyday objects around us.

But
Breit and Wheeler had no expectations that their theory would be proved
any time soon. In their study, the physicists noted that the process
was so rare and hard to produce that it would be “hopeless to try to
observe the pair formation in laboratory experiments”.

Oliver
Pike, the lead researcher on the study, said the process was one of the
most elegant demonstrations of Einstein’s famous relationship that shows
matter and energy are interchangeable currencies. “The Breit-Wheeler
process is the simplest way matter can be made from light and one of the
purest demonstrations of E=mc2,” he said.

Writing in the journal
Nature Photonics, the scientists describe how they could turn light into
matter through a number of separate steps. The first step fires
electrons at a slab of gold to produce a beam of high-energy photons.
Next, they fire a high-energy laser into a tiny gold capsule called a
hohlraum, from the German for “empty room”. This produces light as
bright as that emitted from stars. In the final stage, they send the
first beam of photons into the hohlraum where the two streams of photons
collide.

The scientists’ calculations show that the setup
squeezes enough particles of light with high enough energies into a
small enough volume to create around 100,000 electron-positron pairs.

The
process is one of the most spectacular predictions of a theory called
quantum electrodynamics (QED) that was developed in the run up to the
second world war. “You might call it the most dramatic consequence of
QED and it clearly shows that light and matter are interchangeable,”
Rose told the Guardian.

The scientists hope to demonstrate the
process in the next 12 months. There are a number of sites around the
world that have the technology. One is the huge Omega laser in
Rochester, New York. But another is the Orion laser at Aldermaston, the
atomic weapons facility in Berkshire.

A successful demonstration
will encourage physicists who have been eyeing the prospect of a
photon-photon collider as a tool to study how subatomic particles
behave. “Such a collider could be used to study fundamental physics with
a very clean experimental setup: pure light goes in, matter comes out.
The experiment would be the first demonstration of this,” Pike said.

Andrei
Seryi, director of the John Adams Institute at Oxford University, said:
“It’s breathtaking to think that things we thought are not connected,
can in fact be converted to each other: matter and energy, particles and
light. Would we be able in the future to convert energy into time and
vice versa?”